The mission of the Pathology Core is to provide human and rodent pathology services to the principal investigators in this program project grant. Such services include morphologic assessment, gene expression analysis at the tissue level and microdissection of normal and tumor tissue sections in order to obtain DNA and RNA from pure populations of cells for further analysis. Microdissection is important in the study of gene product expression in prostate pathology that will result from genetic manipulation proposed in the knockout and transgenic models proposed. In addition, assessment of gene expression has a significant role in the identification of novel predictive/prognostic markers and in linking expression differences in human prostate cancer.